1. Field of Invention
This invention pertains to a surgical device for inserting an elongated flexible element having an enlarged proximal end, such an electrode, a probe, a catheter and so on, into a body cavity whereby the element is precisely and easily positioned within the body. The device and method includes the use of a split sleeve which envelopes the element, and which after insertion, can be withdrawn easily and removed from the elongated element without interference from the element proximal end.
2. Description of the Prior Art
Many surgical procedures entail the insertion of an elongated element into a body cavity, which element may be left temporarily, semi-permanently or permanently in the body. For example, one type of such an elongated element is a catheter inserted into a body tissue or organ for the purpose of fluid drainage, fluid infusion, and so on. This type of catheter is provided with an enlarged proximal end, such as Luer connector used for coupling the catheter to a corresponding drainage or infusion device. Another type of flexible element is a probe used for localized tissue treatment using electrical stimulation, heating cooling, radiation, cutting or evacuation. A third type of flexible element is an electrode used for sensing, monitoring and diagnostic functions.
Typically all these elements are place accurately without open surgery by using ultrasonic, endoscopic, fluoroscopic, or X-ray imaging, as well as using stereotactic methods. However a problem with all the elements described above is that because of their very flexibility, it is difficult to feed them and to maneuver them during insertion because the element has insufficient rigidity to pierce or penetrate the various body tissues and/or orifices. This problem has been solved in the past by adding a member which increases the rigidity of the element. However this approach is only possible for elongated elements having a lumen which can accept the rigidifying member. Probes without such a lumen need other stiffening means, such as for example a tube which splits in half along its longitudinal axis after insertion as described U.S. Pat. Nos. 4,166,469;, 4,243,050; 4,345,606.
These latest devices include a tube which receives the flexible element for insertion and later, after the insertion is completed, peels away by separation along a longitudinal frangible zone or line to permit the reinforcing member to be withdrawn past the proximal enlarged end of the elongated element. However this approach is not satisfactory because the required structure can be accomplished with only very thin materials for the reinforcing member whereby the reinforcing member itself is not rigid enough, and also the peeling away can move the flexible element. This problem is especially acute for extra thin elements such as required of example in special applications such as stereotactic brain surgery.
Other systems have been proposed which provide the insertion of the reinforcing element in parallel to the elongated element with locking mechanism such as a hook-and-loop arrangement being provided at the tip or distal end. However this approach is also unsatisfactory because a method or technique must be provided for opening the locking mechanism after the insertion. Moreover, the locking mechanism increases the physical complexity of the elongated element, and its cost.